Art or method of galvanizing metal



(No Model.)

H. K. SWINSGOE.

ART 0R METHOD OF GALVANIZING METAL.

No. 461,251. Patented Oct. 13,1891.

UNITED STATES PATENT OFFIC HENRY K. SVINSCOE, OF CLINTON, MASSACHUSETTS.

ART QR METHOD OF GALVANIZING METAL.

SPECIFICATION forming part of Letters Patent No. 461,251, dated October 13, 1891. Application filed May 26, 1891. Serial No. 394.153. (No model.)

To all whom it may concern.-

Be it known that I, HENRY K. SWINSOOE, of Clinton, county of Worcester, State of Massachusetts, have invented an Improvement in the Art or Method of Galvanizing Metal, of which the following description, in connection with the accompanying drawing, is a specification, like letters on the drawing representing like parts.

Prior to my invention it has been customary to wipe wire cloth or netting after it leaves the bath of molten metal with sand or with coke, as provided for in United States Patent No. 361,550, in order to remove the surplus galvanizing material and impart a luster or polish -t0 the coated wires forming the fabric.

In practice it has been found that coke, which, it is well known, is porous or filled with pockets, becomes, after use, saturated with the molten metal or the oxide thereof, or both, and the coke thereupon loses its efficiency as a wiper, for the following reasons:

First. Its weight being increased by the addition of the metal lodged in the pockets, it does not circulate as freely as when first applied to the molten bath, and so each particle is longer in contact with the wire-cloth, and when it returns to the surface of the metal it descends almost in a perpendicular line, so that in practice after the coke is saturated it presents only a few of its particles to the cloth and becomes soon too hot to wipe efiectually. To restore the efliciency of the Wiper, new or fresh coke must be brought into contact with the wire-cloth.

Second. When the coke is saturated with metal or when the pockets or spaces between the points or projections are filled up to the top or outside thereof with metal, the projections cease to be projections, and thus the chief merit of the coke as a Wiper is destroyed.

Third. Coke, owing to the lack of cohesion and softness, readily permits its points or projections to be worn or broken off by the rubbing together of the particles floating on the bath when put in circulation by the wire cloth or netting passing through them, and thus in another manner is the efficiency of the coke destroyed.

the wire cloth, making it practically unmar-l' ketable.

It will be seen that the first, second, and fourth objections to the use of coke are due to its porosity, and the third is due to its softness. \Vhat I must obtain, then, is a substance that is light, hard, non-porous, and having a sharp angle of fracture. By long experiment, I have discovered that coal-dust fulfills these conditions better than any known material. It possesses the good qualities of the coke and none of its defects. It has the added commercial value of being cheaper than ground or crushed coke and much longer lived.

The drawing shows a sufficient portion of a galvanizing apparatus by which to practice my method. 7

Referring to the drawing, A represents the usual furnace; vB, the kettle containing the molten galvanizing metal; C, the partition therein, having its lower edge immersed in the said metal, E floating flux, and J the metal to be galvanized, it being herein shown as a reticulated fabric or wire-cloth. These parts referred to are and may be all substantially as shown by like letters in United States Patent No; 361,550, referred to. Instead, however, of using coke, as in the said patent, as a wiper, I employ finely-powdered coalthe ordinary coal-dust of commerce, represented at Fthe said coal, owing to its non-porous and non-absorbent nature and owing to its hardness and its many points and angles, being adapted, as before stated, to most thoroughly wipe from the metal being galvanized any surplus of galvanizing metal and at the same time to leave a smooth polished surface, the employment of coal, as stated, besides being better as to the results obtained, being also more economical, not 5 only in first cost but in use owing to its greater durability.

Coal-dust is superior to sand in that the particles are larger and of such irregular shape that a cubic foot of coal-dust is much IOO lighter than a cubic foot of sand, though a wiper composed of coal-dust floating on the there may be but little difference in their respective specific gravities.

I claim That improvement in the art or method of galvanizing or treating wire, wire-cloth, 0r wire-netting which consists in immersing the article to be galvanized or coated in a bath of molten metal and then withdrawing said 10 article or articles from the bath and through surface of the molten metal, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of I two subscribing Witnesses.

HENRY K. SWINSCOE. Witnesses:

BERNICE J. NoYEs, EDWARD I ALLEN. 

